What machine learning can and cannot do

AI is not only for engineers. If you want your organization to become better at using AI, this is the course to tell everyone--especially your non-technical colleagues--to take.
In this course, you will learn:
- The meaning behind common AI terminology, including neural networks, machine learning, deep learning, and data science
- What AI realistically can--and cannot--do
- How to spot opportunities to apply AI to problems in your own organization
- What it feels like to build machine learning and data science projects
- How to work with an AI team and build an AI strategy in your company
- How to navigate ethical and societal discussions surrounding AI
Though this course is largely non-technical, engineers can also take this course to learn the business aspects of AI.

강사:

Andrew Ng

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In this video and the next video, I hope to help you develop intuition about what AI can and cannot do. In practice, before I commit to a specific AI project, I'll usually have either myself or engineers do technical diligence on the project to make sure that it is feasible. This means: looking at the data, look at the input, and output A and B, and just thinking through if this is something AI can really do. What I've seen unfortunately is that some CEOs can have an inflated expectation of AI and can ask engineers to do things that today's AI just cannot do. One of the challenges is that the media, as well as the academic literature, tends to only report on positive results or success stories using AI, and we see a string of success stories and no failure stories, people sometimes think AI can do everything. Unfortunately, that's just not true. So, what I want to do in this and in the next video, is to show you a few examples of what today's AI technology can do, but also what it cannot do, and I hope that this will help you, hone your intuition about what might be more or less promising projects to select for your company. Previously, you saw this list of AI applications from spam filtering to speech recognition, to machine translation, and so on. One imperfect rule of thumb you can use to decide what supervised learning may or may not be able to do is that, pretty much anything you could do with a second of thought, we can probably now or soon automate using supervised learning, using this input-output mapping. So for example, in order to determine the position of other cars, that's something that you can do with less than a second. In order to tell if a phone is scratched, you can look at it and you can tell in less than a second. In order to understand or at least transcribe what was said, it doesn't take that many seconds of thought. While this is an imperfect rule of thumb, it maybe gives you a way to quickly think of some examples of tasks that AI systems can do. Whereas in contrast, something that AI today cannot do would be: to analyze a market and write a 50 page report, a human cannot write a 50 page mark of analysis report in a second, and it's very difficult, at least I don't know. I don't think any team in the world today knows how to get an AI system to do market research and run an extended market report either. I've found out one of the best ways to hone intuition is to look at concrete examples. So, let's take a look at a specific example, relating to customer support automation. Let's see a random website that sells things, so an e-commerce company, and you have a customer support division that gets an email like this, "The toy arrived two days late, so I wasn't able to give it to my niece for her birthday. Can I return it?" If what you want is an AI system that looks at this and decides this is a refund request, so let me route it to my refund department, then I will say, you have a good chance of building an AI system to do that. The AI system would take as input, the customer text, what the customer emails you, and it would output, is this a refund requests or is this a shipping problem, or is it the other request, in order to route this email to the most appropriate parts of your customer support center. So, the input A is the text and the output B is one of these three outcomes, is it a refund or a shipping problem, or shipping query, or is it a different requests. So, this is something that AI today can do. Here's something that AI today cannot do which is if you want the AI to input an email and automatically generate, it responds like, "Oh, sorry to hear that. I hope you're niece had a good birthday. Yes, we can help with, and so on." So, for an AI to output a complicated piece of text like this today is very difficult by today's standards of AI and in fact to even empathize about the birthday of your niece, that is very difficult to do for every single possible type of email you might receive. Now, what would happen if you were to use a machine learning tool like a deep learning algorithm to try to do this anyway. So, let's say you tried to get an AI system to input the user's email, and output a two to the three paragraph, empathetic and appropriate response. Let's say that you have a modest-sized dataset like a 1,000 examples of user emails and appropriate responses. It turns out if you run an AI system on this type of data, on a small dataset like 1,000 examples, this may be the performance you get, which is if a user emails, "My box was damaged," they'll say, "Thank you for your email," and it says, "Where do I write a review?", "Thank you email." "What's the return policy?", "Thank you for your email." But the problem with building this type of AI is that with just a 1,000 examples, there's just not enough data for an AI system to learn how to write to the three paragraph, appropriate and empathetic responses. So, you may end up just generating the same very simple response like, "Thank you for your email," no matter what the customer is sending you. Another thing that could go wrong, another way for an AI system to fail is if it generates gibberish such as: "When is my box arriving," and it says, "Thank, yes, now your," gibberish. This is a hard enough problem that even with 10,000 or a 100,000 email examples, I don't know if that would be enough data for an AI system to do this well. The rules for what AI can and cannot do are not hardened first and I usually end up having to ask engineering teams to sometimes spend a few weeks doing deep technical diligence to decide for myself if a project is feasible. But to hone your intuitions to help you quickly filter feasible or not feasible projects, here are a couple of other rules of thumb about what makes a machine learning problem easier or more likely to be feasible. One, learning a simple concept is more likely to be feasible. Well, what does a simple concept mean? There's no formal definition of that but it is something that takes you less than a second of mental thought or a very small number of seconds of mental thought to come up with a conclusion then that would lean to whether it being a simple concept. So, you're looking outside the window of a self-driving car to spot the other cars that would be a relatively simple concept. Whereas how to write an empathetic response, so a complicated user complaints, that would be less of a simple concept. Second, a machine learning problem is more likely to be feasible if you have lots of data available. Here, our data means both the input A and the output B, that you want the AI system to have in your A to B, input to output mapping. So for example, in the customer support application, the input A would be examples of emails from customers and B could be labeling each of these customer emails as to whether it's a refund requests or a shipping query, or some other problem, one of three outcomes. Then if you have thousands of emails with both A and B, then the odds of you building a machine learning system to do that would be pretty good. AI is the new electricity and it's transforming every industry, but it's also not magic and it can't do everything under the sun. I hope that this video started to help you hone your intuitions about what it can and cannot do, and increase the odds of your selecting feasible and valuable projects for maybe your teams to try working on. In order to help you continue developing your intuition, I would like to show you more examples of what AI can and cannot do. Let's go into the next video.